The present invention relates to a method of and a cutting press for separating such parts from a workpiece plate which because of their dimensions cannot fall through an opening in a lower tool.
It is known to separate parts on a cutting press which has an immovable support surrounding the operating region of the tool, a controlled coordinate table for positioning of a workpiece and having two lateral workpiece supports movable parallel to the y-axis and defining a space therebetween for the movable support, and a guiding rail connecting the lateral workpiece supports and having a transverse carriage displaceable in the direction of the x-axis and having clamping elements for the workpiece plate, and a central workpiece support located between the lateral workpiece supports before the immovable support and including a plurality of articulately connected supporting elements. The supporting elements are supported and guided relatively movable in guide paths arranged on the lateral workpiece supports and displaceable therewith with the path course directed downwardly in the region of the clamping elements of the transverse carriage. The supporting elements are pulled back by special pulling means in the direction of the y-axis from the immovable support so that between the immovable support and the first supporting element facing thereto a discharge opening for the separated parts of the previously withdrawn workpiece plate is opened and by the respective return movement of the supporting elements is closed. A cutting press, especially a revolving cutting press of the above mentioned type is disclosed in U.S. patent application Ser. No. 405,336, now U.S. Pat. No. 4,452,115. The discharge openings formed by the displaceable central workpiece support provides for a possibility to withdraw the cut out or separated parts of the workpiece plate not through the opening of the lower tool because of their dimensions, but to withdraw them automatically without distortion of other machine steps through the discharge opening.
It has been shown from practice that during the operation of such a cutting press there are difficulties when relatively thin workpiece plates or sheets are worked. These difficulties include the following: The cut out workpiece parts must be withdrawn with the remaining workpiece plate from the tool operating region, and the coordinate table must displace in the direction of the y-axis to bring the cut out workpiece part for discharge on the central workpiece support so as to discharge this workpiece part after release of the discharge opening. It has been shown that during working of relatively thin workpiece plates or sheets the cut out workpiece part and the remaining workpiece plate move over one another, whereby a safe fall or withdrawal of the cut out workpiece parts through the discharge opening is hampered or made completely impossible.